Electric-wave amplifier.



H. DE P. ARNOLD.

v ELECTRIC WAVE AMPLIFIER.

APPLIOAIION FILED MAY 16, 1914.

1, 1 2,279, Patentgd Feb. 16, 191 5.-

W/fneaSes:

-; output circuit a perfect form reproduction UNITED si'Es PATENT OFFICE.

HAROLD DE FOREST ARNOLD, OF EAST ORANGE, NEW JERSEY, ASSIGNOR T0 WESTERN ELECTRIC COMPANY, OF NEW YORK, N. Y., A CORPORATION OF ILLINOIS.

-. ELECTRIC-WAVE AMPLIFIER.

Y Specification 01 Letters Patent.

Patented Feb. 16, 191 5.

Application filed May 16, 1914. Serial N 0. 839,057.

To all whom it may concern Be it known that I, HAROLD DE FOREST ARNOLD, a citizen of the United States, residing at East Orange, in the county of Essex and State of New Jersey, have invented a certain new and useful Improvement in Electric-Wave Amplifiers, of which the following is a full, clear, concise, and

. and amplifying alternating current waves of small magnitude.

The principal parts of an audion element or structure are a heated filament or other source of ionization, an anode usually called a plate, and an electrode, preferably located intermediate the filament and the plate, said electrode being usually called a grid. These are preferably inclosed in an evacuated glass vessel. Characteristic features of the audion are that current can flow in one direction only in the ionized stream, and that the strength of current in the stream flowing from its source to the late is modified by electrostatic rather than y electromagnetic force as in some other types of gaseous repeaters.

A simple arrangement for using a single audion element as a repeater is as follows: The input circuit is connected, one side to the filament and the other to the grid, while the output circuit is connected, one side to the filament and the other to the plate. Repeating coils are preferably employed in the input and output circuits respectively, and a battery is included in the output circuit in series with the primary winding of the output repeating coil. The audion re-' peater as" thus used, although a powerful amplifying agent, does not repeat in the between the filament and the grid has uni-.

lateral conductivity. hen an alternating potential is applied between the filament and the grid, current flows during that part of each wave cycle in which the grid is positive, but little or no current flows in this circuit during the other part when the grid is negative. This unsymmetrical action results in a certain amount of distortion in the output waves which is avoided, in accordance with this invention, by employing two audion ele ments, one of which operates to repeat the positive parts and the other the negative parts of the input waves. Two audion elements-may be combined in one structure for this purpose, and the present invention is an improvement in that disclosed in the application of Edwin H. Colpitts, Ser. No. 810,196, filed Jan. 3, 1914.

In the drawings-Figure 1 represents a.

tion are represented in the several views by the wires 1, 2 terminating in the primary winding 3 of an input repeating coil 4:, and the wires 5, 6 terminating in the secondary winding 7 of an output repeating coil 8 respectively. The secondary of the repeating coil 4 comprises two distinct windings 9 and 10, and the primary winding of the repeating coil 8 is divided into two coils 11 and 12.

,Two audion elements are combined and included in each ofthe circuits. They comprise two heated filaments 13 and 14, an anode or plate 15, and two intermediate electrodes or grids 17 and18. Each of the filaments is heated by current from a battery 19. The output circuit, including the primary coils 11 and 12 of the repeating coil 8, has included in a common portion of it a battery 21. In each of the systems, shown in Figs. 1 and 2, there are employed three classes of circuits exclusive of the incoming and outgoing line circuits. One is the circuit of eachof the heated filaments fed by the battery 19. In the second class are the two oppositely connected input circuits, each of which includes one of the secondary windings 9, 10 of the repeating coil 4, one of the grids 17 and 18,ja portion of the ionized stream and one of the filaments.

includes in the common portion the battery 21 and in the divided portions the heated filaments 13, 14, the ionized streams, the

anode 15, and the primary coils 11, 12 of the repeating coil 8.

In Fig. 1 a telephone line is represented in which one repeating set of two audion elements may be employed to provide for com mercial two-way telephonic transmission between two stations A. andB. 'T he primary winding 3 of the input repeating coil 4 is divided into four coils, as shown, and its several coils are included serially in the telephone line, while the secondary winding 7 of the outputrepeating coil 8 is placed in bridge of the telephone line and connectedw -l. In an electric wave repeating appasymmetrically with respect to the several coils of the primary winding 3. In Fig. 2 are-showntwo similarrepeating sets to provide, in another way, for commercial two-way service. T he. telephone line is divided and the two partsiseparately balanced by networks 22 and 23, respectively. The primary winding 3 of the input repeating coild of one of the repeater sets is divided into four coilswhich are included serially in the telephone line extending between the telephone station A and the network 22. In the same way four coils of the primary winding 3 of the repeating coil 4 of the other set are included serially in the line extendingbe tween thetelcphone station E and the net work 23. j

The operation is as follows: Telephoni currents or other electric current waves in- .coming by way of conductors 1, 2 are received in the primary winding 3 of the input repeating coil 4:, and reproduced by the secondary windings 9, 10 thereof in the input circuit. At any instant of time, except of course at the moment when a wave is passing the point of zero current flow, there will be positive potential impressed on one of the grids, say 17, and a corresponding negative potential impressed on the other grid, 18. As current can flow between the heated filament and the grid of either audion.

element only when the grid isat positive potential with respect to the-filament, the effect on the current in the'ionized stream flowing between the filament and plate will be different in the two audion elements. The

grid which is for the moment positive will.

materially alter the flow of current in the stream in which it is interposed, but the grid which at the same moment is negative will have little or no efi'ect. As the electric curreversed so that the negative portion of the wave (assuming the other portion considered Q tohave been positive) will be repeated due to positive potential on the previously inefiiective grid. Thu's'every variation in our- The third is the divided output circuit which rentproduced by the input waves -is re pea'ted by one orthe other ofth'e two audion elements' A suitable structure for the combined audion elements'is shown in Fig.3, wherein the filaments 13, "14 aresupported from one end of the: glass bulb'or vessel 24:- The two grids 17, 18 and the plate 15 are supported at the'other end ofthe vessel and held in their proper positions in'any suitable manner. llhe grids 17, 18 are connected to the leading in wires 25, 25 respectively. A leading-in wire 26 is provided for the plate 15, and a pair of leading-in Wires 27, 28 are provided for each of the filaments 13, 14.

What is claimed is:

ratus, a'unitary audion structure comprising -a plurality of filaments, input electrodes 4, In an electric .wave repeating apparatus, a plurality of audion elements meluded in'a unitary structure comprising a plurality of filaments and their corresponding grids and an anode common to said audion elements.

5.111 an electric Wave repeating apparatus, two audion elements included in a unitary structure comprising two filaments, two grids located between said filaments, and a plate between said grids.

6. In an electric wave repeating apparatus, the combination of two repeating elements comprising a cathode and an anode individual to each of said elements and an anode common to said elements, an input repeating coil having two secondary windwinding and the ends of said primary wind-' ing being connected to said filaments, respectively.

7 In an electric wave repeating apparatus, the combinationof two audion elements having-a. common plate and individual filaments and grids, an input repeating coil having secondary windings oppositely connected in circuit with said filaments and grids, and an output repeating coil, the

:pnmary winding of which is connected at an intermediate point to said plate and at its opposite terminals to said filaments.

HAROLD DE FOREST ARNOLD.

- Witnesses: v

KATHERINE L. STAHL, ELLA EDLER. 

